The conventional method of mounting a frame, such as a window or a door frame, within an opening of a wall structure is to position the frame within the opening which is made slightly larger than the outer periphery of the frame and the level thereof is then adjusted by securing wooden shims, usually cedar shingle pieces which vary in thickness from end to end, within the space around the frame. These shingle pieces are usually longer than the width of the frame and need to be cut flush with the frame after these have been installed and the frame is leveled. It is thereafter necessary to secure the window frame to the opening in the wall structure, and this is done by inserting fasteners, such as nails or screws, within the frame from the outside and into the peripheral members forming the wall structure. The fasteners then have to be concealed by paint or otherwise.
A disadvantage of this conventional method is that it is time consuming, and these shingles also cause problems. For example, because the shingles extend across the frame, it is very difficult to provide a uniform caulking seal about the frame. It is also not possible to provide a continuous insulation about the periphery of the frame in the exterior region thereof, between the frame and the opening, as the shingles present an interference. Furthermore, when constructing housing structures the wooden material utilized is usually not completely dry, and after a year or more these wooden pieces utilized in the construction of a wall structure will twist and change positions thereby causing variations in the space between the frame and the opening. Such movement in the structural materials will cause voids about the shingles, and this will result in causing the caulking to crack in the area of the shingles and air will infiltrate. Furthermore, the space defined about the window frame and the opening in the wall structure will vary somewhat causing the window frame to de-level itself. This would then cause a further disadvantage in that the window panes will not slide effectively if the frame becomes unleveled. It is also pointed out that when the window frame is shimmed with wooden pieces, any movement in the wall structure about the frame will be transferred directly to the frame of the window by the fasteners, and this can lead to deformation of the frame, rendering the window pane inoperable and often causing the glass pane to crack or break. The fasteners will also crack the frame and become unsightly.
The process of leveling the windows by using wooden shingle shims is also time consuming, and often there is insufficient number of shims, or the shims are placed in improper areas to provide for an efficient window or door frame installation.
In order to remedy this problem shimming devices have been developed but have not heretofore been adequate to resolve the above-mentioned problems. A typical example of such shim device is described in U.S. Pat. No. 3,571,996 wherein the device provides an adjustment by means of a screw which is accessible from the exterior of the frame.